


The Duality of Man

by Xx_SmutAnge_xX



Series: Shitty Fire Emblem Smut [1]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Cheesy, Consensual Sex, Creampie, F/M, First Time, First Time Blow Jobs, Fluff and Smut, Forbidden Love, Loss of Virginity, Love Confessions, Making Out, Nipple Play, Riding, Teacher-Student Relationship
Language: English
Status: Completed
Published: 2019-03-18
Updated: 2019-03-18
Packaged: 2019-11-23 23:57:31
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18158753
Author URL: https://archiveofourown.org/users/Xx_SmutAnge_xX/pseuds/Xx_SmutAnge_xX
Summary: Byleth's been teaching at the Officer's Academy for a few months now, and Edelgard's always been something of a star pupil. As she becomes more and more aggressive, however, Byleth finds himself feeling emotions beyond the realm of professionalism...





	The Duality of Man

**Author's Note:**

> Well, this definitely wasn't how I planned on spending my weekend. This probably won’t age well, but I did it anyway because I've got nothing to lose! Speaking of age, I have no clue how old Edelgard is supposed to be, but I picture her as being around 18 so that is what we're going with here. 
> 
> Also, if student-teacher things squick you out, this probably isn’t going to change your mind. Viewer discretion is advised!

Even as a child, Byleth scoffed at the idea of becoming a teacher. His mother had been a quite accomplished educator in her own right, but he always preferred the way of the sword.

As one might imagine, he was more than a little confused when the esteemed Church of Seiros offered him the position of instructor at the Officer’s Academy. And all at the ripe age of twenty-one, to boot.

Byleth got on well enough with the other teachers and students. Though many gave a warm welcome, he hid behind a wall of stoicism. Some might have called him curt, but Byleth was afraid. Afraid that their trust in him might be misplaced. Afraid that his fighting expertise would be of little help when teaching was involved. Afraid that he might develop feelings for one of the many attractive young students he now instructed.

That last fear, he now realized, was entirely reasonable.

Until now, Byleth had never met a woman quite like Edelgard. The future empress of the Adrestian Empire was far more fiery than she appeared at first glance; a fire blazed within her that could give Dimitri a run for him money, and this surprised Byleth in more than one way. He admired her bravery and willingness to learn, but Edelgard could be rather… blunt, with what she desired. 

And what she desired, above nearly all else, was  _ him _ .

“This is wrong,” Byleth said with disdain as he sat at his desk. His previous interaction with her still lingered in his mind. He’d been enjoying lunch with the other teachers when Edelgard had called him away, ostensibly to discuss strategy. 

_ “Professor,”  _ she has said once the two were alone, well away from prying eyes and ears.  _ “I… I think I might be in love with you…” _

A tear rolled down Byleth’s cheek as he fumbled with some paperwork. He eventually gave up, leaning forward with both hands in his hair and his elbows on the desk. “Edelgard, I… Gods, but I want you too… Why must this be so difficult?”

As a simple mercenary, this wouldn’t have been much of a moral dilemma for Byleth. True, Edelgard would still be the future empress of a nation that comprises half of Fódlan, but… 

He sighed and reached under his desk, finding an unopened bottle of wine. He poured himself a glass and took in the dark, smooth taste. This wasn’t fair; if he’d been taken in as a student instead, he wouldn’t even be having this issue, nor would he have everyone’s fighting education riding on his shoulders.

And Edelgard… sweet,  _ wonderful  _ Edelgard… she’d completely caught him off guard. Never before had he met a woman who could swing an axe with such strength, such  _ grace _ ! Her tongue was as sharp at times as her wit, but it only made her all the more fun to converse with. Above all else, Byleth valued her strong will and her loyalty to the other Black Eagles. Not once did she disparage them, and she always strived to treat them as equals despite their difference in station.

_ A true egalitarian. _

He took another sip, relishing the feeling of euphoria the wine gave him. He never liked drinking on a school night, but he’d have to make an exception this time. Just until he could get Edelgard out of his head. Just until he could regain his professionalism…

“Father… What would you do…?”

 

* * *

Edelgard rested in her luxurious bed, hands clasped above her stomach as she stared up at the ceiling. By all accounts, today had been a success; the Black Eagles successfully saved a nearby village from a group of bandits, training had gone well, and the three houses seemed no more at odds with each other than usual.

But Byleth…

“Does he just not like me?” she asked herself. “Does he not even care? ‘We’ll talk later, Edelgard’... Ugh. Now I’ve done it.”

In truth, Edelgard was no stranger to matters of the heart. She’d had crushes on several boys during her childhood. Byleth brought a certain air of both wisdom and maturity, however. When they first met, it was in the company of his father’s mercenary group. Captain Jerat was friendly enough, but Byleth seemed comparably more mysterious and standoffish. Even Claude and Dimitri took note of it.

And yet, his stern face and impassionate words hid a softer side. 

Whenever some of the younger students would miss a target during archery or put up a poor fight in a mock battle, Byleth would be there with advice rather than disparagement. He kept himself at arm’s length with students and faculty alike, but he’d been nothing but helpful since he arrived. Edelgard sensed a bright future in store for him, and it was one she hoped she could partake in too…

… Even as the future empress of the Adrestian Empire.

“Is that why he turned me away? Is he intimidated by me? … Or is there something else going on?”

Edelgard groaned and turned on her side. Maybe she’d ask Claude or Dimitri about him tomorrow. Byleth was a professor, sure, but he was also a man. Who knows what sorts of secrets he’d divulge with them?

“... Wait.” Her eyes shot open. “ _ Teacher _ … Could that be why…?”

* * *

The next morning, Byleth oversaw the students’ archery practice. Ashe and Bernadetta in particular showed promise with the bow, even if the latter nearly shot him a couple of times. Byleth only had himself to blame; he  _ had  _ insisted that they practice using the real deal, after all. It was a wonder the other teachers even agreed to his methods to begin with…

Byleth nodded in approval when Claude launched two arrows into the same target, the second splitting the first right down the middle as it hit dead-center. 

_ Bonus points for being able to shoot a bow in mid-air…  _

He was taken out of his thoughts when an arrow landed a few feet away from him, planting its head in the dirt. However, Byleth was more concerned with the piece of paper attached to it. Everyone else seemed too focused on their studies to care, so he snatched the paper up and began to read it in his mind. 

 

_ Dearest ‘Professor’, _

_ Please meet me in your quarters after sundown. I believe we still have some important business to discuss.  _

_ ~ E. Von Hræsvelgr _

 

“Subtle.” Byleth chuckled under his breath as he stashed the note in his coat. “Very subtle…”

“Who’s subtle?” 

He whirled around to come face-to-face with a very sweaty Dimitri. He recomposed himself and said, “Nobody. Please resume your training activities.” 

“C’mon, you  _ know  _ I’m much better at using the spear.” 

“Are you in need of a new sparring partner, Dimitri? If that’s the case, I am more than happy to oblige.” 

“Ha! We’ll see who trumps who, Professor!” 

* * *

Edelgard sat at the edge of Byleth’s bed, wringing her hands together. She looked out the window and saw that the sun had sank below the horizon, allowing its sister to take over. A few well-placed lanterns kept the room alight, but Edelgard herself was more focused with her professor. “... Maybe he had some extra paperwork…”

Her thoughts turned to the door when she noticed the handle turn. Her heart nearly did a flip as Byleth appeared, overcoat and all. He was usually rather stone-faced, but Edelgard could have sworn he nearly did a double-take as he spotted her. “... Edelgard? How did you even get in here?” 

“Please, sit,” she urged, motioning to the spot beside her on the bet. Byleth looked her up and down as if she had suddenly sprouted three heads, but reluctantly shut the door behind him. Still, he refused to sit, opting to stand before the foot of the bed instead. “... Professor, I - “ 

“Edelgard,  _ please _ … surely you must know how wrong this looks.” 

“But I still need to talk to you!” 

“Couldn’t this have waited until tomorrow morning?” he asked. “... Preferably in a less personal place than this?”  

Her lilac gaze sharpened as she narrowed her eyes at him. “Professor… just hear me out. Please.” 

“But… I…” He took one look at her and sighed. Edelhard was a strong woman, but with that strength came the stubbornness of a mule. Byleth finally relented after a few moments of silence. “... Very well. Tell me, Miss von Hræsvelgr, what brings you to my humble abode at this, a most inconvenient hour?”

“You and your snark.” She pouted, glaring at him. Her gaze fell to the floor as her expression softened a bit. She took a deep breath before going on. “... As you can imagine, this is about what I said yesterday.”

“Edelgard…”

“Is it me?” she questioned, staring back at him in uncertainty. “Am I just not attractive enough for you?”

Byleth recoiled a bit. “Your physical appearance has nothing to do with - “

“Is that so?”

“Edelgard, I implore you to listen to me - “

“Just…” She paused, taking another deep breath. She wasn’t one to lose her nerve, but her next words came out in a shaky tone. “... Just tell me you don’t love me.”

“I… What?!”

She snorted. “That must be why you don’t want anything to do with me, correct? I’m sure that someone else has already caught your eye by now. Like Dorothea, or Petra, or - “

“Edelgard, no! You are a student and the future empress of the Adrestian Empire,” Byleth explained, strain in his voice, “while I am your teacher.” He took a step forward, waving a hand for emphasis like he usually did during his lectures. “Do you not see the problem here? Were I to act upon my feelings, I would be taking advantage of my position! Viewing you as just another student and remaining unbiased would be impossible!”

Edelgard stood up from the bed, closing some of the distance between them. “What if I don’t want you to see me as ‘just another student’? What if I want to be more to you than that?”

Byleth’s words were caught in his throat as he struggled to come up with a response. Edelgard, meanwhile, took another bold step forward. Her eyebrows creased downward as she gazed into his eyes longingly. “... Byleth, I…”

By now, a million thoughts were racing through his head. On the one hand, this could mean the end of everything for him. Here he was, holding one of the most prestigious positions in all the land, with enough pay and security to let him live comfortably for years to come… yet it could all come crashing down the moment he allowed his true feelings to shine through.

But on the other hand, she smelled so damn good… it was as if she had bathed right before coming here, using only the finest lavender soap… 

Byleth, Sothis called out to him from the innermost recesses of his mind. Let go.

Just like that, Byleth had thrown all caution to the wind and embraced Edelgard. She gasped when he buried his face the crook of her neck, taking in her magnificent scent. She wrapped her arms around his torso and let out a small moan as he dragged his tongue up her neck. It trailed across her chin before his lips finally met hers, and Edelgard squeaked as she melted into the kiss. The two fell onto the bed, Edelgard’s back meeting the sheets as Byleth continued to pepper her lips and neck with kisses. They were clumsy to be sure, but it wasn’t as if she had any actual experience to compare him to.

“Haah… hnng.” She gasped and clutched at his back as he continued to suckle her sensitive flesh. Byleth kept at it for a few more minutes before pulling back from her, holding himself above her with an arm on either side of her. Her face was positively flushed as she struggled to catch her breath, meeting his gaze with half-lidded eyes. “P-p-professor…”

“I’m sorry, Edelgard,” he apologized, panting. “I… I don’t know what came over me - !”

She suddenly wrapped her arms around his neck and pulled him back into a kiss. She was just as rough as he had been, mashing her lips against his. Finesse be damned; she needed this.

She needed him.

In her lust, Edelgard had rolled Byleth over so that he was underneath her. She grabbed both of his wrists above his head and held them there, rendering him powerless to resist her onslaught of fiery kisses. She suddenly thrust her hips against his nether regions, and Byleth’s shock allowed her to force her tongue inside his mouth.

“Mm...ngh…”

She continued to dry hump him, releasing her grip on his wrists in favor of grabbing fistfuls of teal hair. Byleth rested his hands on Edelgard’s hips and pulled her closer, grunting each time she ground against his rapidly-growing erection.

“Mhm… wait,” he said, pushing her away slightly. Edelgard let out a whimper as the kiss was broken, her lips slightly swollen. “Let’s not… ruin our uniforms, eh?”

She let out a small giggle as the heat flew to her ears. “Heh… right…”

Byleth was the first to disrobe, setting his clothes by the foot of his bed and stopping only when he was down to his black smallclothes. Edelgard couldn’t say she was shocked to see his toned chest and stomach; being a mercenary was hard work. Several scars lined his body, clear signs of hardship. As her eyes continued to scan him, Byleth rubbed his arm and looked off to the side. 

_Ridiculous_ , he chided himself. Not ten seconds ago you were getting frisky with her, and now you choose to get shy? You’re pathetic, Byleth. Pathetic!

“... You’re beautiful,” Edelgard said at last, still staring at his nearly nude form.

If Byleth’s face hadn’t already been red from their passionate session, it surely would have flared up then and there. “I… H-huh?”

Without warning, Edelgard leaned over and pressed a kiss to his chest. The act made him shiver, and she looked up at him with concerned violet eyes. “O-oh? Did that hurt you?”

Byleth shook his head. Edelgard took this as a sign to continue, and she laid kisses all along his pectorals and sternum. These kisses were far softer than the ones she’d placed upon his lips, each reminding him of the angels portrayed in some of the Church of Seiros’s murals.

Goddess forgive me.

Edelgard’s kisses gradually became lower and lower until they passed his navel and reached the part of skin between his stomach and what remained under his smallclothes. She looked up and him and blinked, a thumb already hooked under either side of them. “M-may I…?”

He nodded, and Edelgard wasted no time in pulling them down and releasing the beast within. She let out a small gasp at the sight of Byleth’s cock, watching it stand at attention in the cool bedroom air. A patch of teal pubes rested above his shaft, and his balls hung below. Edelgard had passed her anatomy course with flying colors, but to see an actual penis in the flesh - and that of the man she adored, no less…

“Edelgard?” Byleth asked, his face still beet-red. “You’ve been staring for some time now…”

“H-have I?” It was then she realized that she had been drooling a bit as well. She hastily wiped the saliva away before looking back up at him. “... Um, Byleth…?”

“Yes?”

“May I… touch it?”

_By the Goddess! How cute could one girl **be**?!_

“... You may.”

Edelgard returned her attention to his cock and reached a tentative hand forward. She slowly grasped it, running her thumb across the top. Byleth covered his mouth and let out a quiet moan, causing her to look back up at him with a renewed sense of empowerment. She began to pump it in slow, agonizing strokes, using her other hand to gently cup and fondle his balls. It wasn’t long before his tip began to secrete a clear fluid. 

“Ah… oh, Edelgard…”

“Mm…” She swirled the tip of her index finger around his glans, taking note of the sticky fluid. “Interesting… Does this mean it’s working?”

“H-hey,” he blurted, getting her attention. “... This is a little embarrassing, you know? You’re still fully-clothed, and I’m…”

Edelgard’s face went red as her gaze drifted to her attire. “Ah… r-right. Well then…” 

She backed away from him and started to undress. It wasn’t as if she was ashamed of her physique - far from it - but she couldn’t help but think about how girls like Dorothea and Petra had… filled out their blouses, so to speak. Her fingers fumbled with the clasp of her cloak, letting the red fabric fall to the floor. Her other clothes quickly joined them, and Edelgard only stopped when she was left in her undergarments. She averted his gaze as she lowered herself back to his groin. “... Satisfied?” 

“Y-yes, of course,” Byleth said, nodding dumbly. Edelgard’s skin was pale and creamy, and her toned body was complimented wonderfully by her light purple bra and panties. Her breasts were considerably small, but it mattered little to Byleth. He’d always found her beautiful, but at this moment in time, she was  _ radiant _ . “... You look great.” 

“Hee hee… Thanks.” Edelgard wasted no time in stroking his length once more. Byleth’s compliment had given her a renewed sense of confidence, and the fluid still leaking from his tip only egged her on. She leaned her head down and gave it a tentative lick. Byleth shuddered and recoiled, causing her to glance up at him. “Did that hurt? I’m sorry…” 

“N-no! You… that felt good…” 

“Oh? Well, in that case…” 

She continued to fellate him, her soft pink tongue delivering quick flicks to his head. As it glided across the tip smoothly, she continued to pump the shaft with one hand and massage his balls with the other. Byleth leaned back and bit his lip, almost afraid to ask just where she learned the technique. The older mercs he’d spent time with often laughed and joked about something called a “blowjob”, but… was this it? Was this what he’d been missing out on this whole time?

_ Such passion… such vigor!  _

His toes curled, and he placed both hands on Edelgard’s head. She looked up at him with devious eyes before taking the tip in her mouth entirely. Byleth winced when he felt teeth, but Edelgard must have picked up on it as her jaw dropped, allowing her to take in more of his cock. Never before had he felt such warmth. “E… Edelgard…!”

Yes, she thought, grabbing his hips as she grew even bolder. She took a few inches in, her jaw dropping further to accommodate him. Say my name. Say it!

“Edelgard!” Byleth grasped her head and held it in place as his hips began to push forward. She nearly gagged as his tip hit the back of her throat, but she maintained her composure. She pulled back and released her grip on his cock, coughing. “Oh, oh no… Edelgard, I’m so sorry… I should have been less rough - “

She pressed a finger to his lips. When she looked up at him, any anger he expected to find was gone. Edelgard’s eyes were half-lidded as she panted. “Hh… it… it’s fine… I just need some more practice, that’s all…”

Byleth leaned down and met her in a gentle kiss, two fingers tilting her chin upward. They stayed like that for quite some time, Edelgard wrapping her arms around his neck as he kissed her softly. She’d be lying if she said she hadn’t enjoyed Byleth’s rougher side to some degree, but this… this worked too...

Edelgard broke the kiss and rested her forehead against his, staring dreamily into his eyes. “Prof… Byleth. I love you... ”

“I… I love you too, Edelgard,” he said, holding her close. He was almost certain that he’d go to Hell for this, but he didn’t care anymore. He said what he meant, and he meant what he said. “Truly. You… you complete me.”

She giggled quietly. “Been reading a few romance novels in your spare time, haven’t you?”

Byleth looked away in shame as she pressed her lips to his cheek. “... I think it’s kinda cute.”

“Ah… th-that’s…”

She pushed him onto the bed before he could finish whatever thought he had. Staring at his erection, Edelgard bit her lip and pulled down her panties.

“Edelgard?” Byleth blurted. He looked down and blushed. A curly mass of white hair rested above her muff, and her lower lips were already slick with arousal. “... Are you sure this is what you want?”

“I am,” she insisted, reaching behind her back and unclasping her bra. The last of her clothing fell to her feet, exposing her small breasts to him. She climbed over him and carefully positioned herself so that she hovered right above his cock. She shuddered as the tip brushed against her pussy. “I… I’ve wanted this for a long time now, Byleth. There’s no one else for me…”

“I… ah…” He shut his eyes as he was partially engulfed in her folds. Edelgard’s mouth had been warm, but this… this was divine. He wanted to give everything to her then and there, but he’d been told a girl’s first time could be rather painful. Besides, she seemed as though she wanted to take control. For the time being, he resolved to pleasure her in other ways. His hands flew to Edelgard’s breasts, giving them a gentle squeeze.

“A-ah!”

“Sorry, I should have - “

“N-no,” Edelgard whimpered, “it feels good…”

Byleth continued to fondle her snowy mounds as she sank further down at an almost painstaking pace. She winced, biting her lip as his cock finally reached her barrier. Edelgard had experimented with her fingers before, but this was a new beast altogether. The books had said there would be some pain at first, maybe even some bleeding were she too rough, and so she resolved to proceed with caution.

Edelgard gasped when Byleth’s thumbs brushed against her nipples. He took one between his thumb and index finger, giving it a small tug. “B-Byleth… aah…”

“Is this alright?”

“Yes,” she cooed, her face flushing. “Um… c-could you use your mouth?”

“Like so?” He reached upward to take a nipple into his mouth. Edelgard sighed with a content grin as she felt his warmth overcome her.

“Teeth… use your teeth…”

Byleth did as he was told, taking the nub in his teeth. He bit down gently, eliciting another moan from her. As he continued to toy with her, Edelgard sank down further onto his cock with a gasp. She could feel her inner walls expanding as he finally passed through her barrier. She hissed through grit teeth as an indescribable pain washed over her.

“Edelgard?” Byleth asked in a soft tone, his eyebrows raised in concern. He moved a hand upward to cup her cheek. “Are you alright? … Should we stop?”

“I… I’ll be fine in a minute,” she said through ragged breaths. Edelgard felt her face grow hot when she saw Byleth staring back at her with those piercing eyes of his. His eyes, ordinarily stern, were now full of compassion and love. “I… Byleth?”

“Yes?”

Edelgard promptly leaned down to kiss him. “I love you…”

He blushed, but kissed her back. “And I you, my dear…”

They sat together in silence for a few minutes, arms wrapped around each other and hands in each other’s hair as Edelgard waited for the pain to subside. Once it’d gotten to a more manageable point, she took charge once more and placed her hands on his chest. As she lifted herself up and down, Byleth rested a hand on either of her soft hips. She wasn’t exactly the most curvaceous of his students, but it didn’t matter.

“Hng… haah... “

“D-don’t strain yourself,” he warned her, shutting an eye.

“H-heheh,” she laughed. Almost as if to spite him, Edelgard’s pace seemed to increase as she bounced up and down on his cock. “I’m feeling much better now, actually… What say you?”

Without warning, she grabbed his wrists and held them above his head so that he was pinned to the bed. Byleth gasped as she continued to take charge, fucking him like it was her last time. He couldn’t help but moan as he felt his cock slide in and out of her, and Edelgard took the opportunity to force her needy tongue into his mouth.

All he could do was kiss her back.

“Mmm… mwah.” Edelgard ran her fingers through long teal hair as she continued to press her lips to his. A crafty Byleth took advantage of the situation to grab her hands and hold them in his own. He began to thrust his hips from under her, matching her intensity. “A-aah!”

“Y-you have much yet to learn,” Byleth teased.

She smiled as her grip tightened. With a mischievous glint in her eye, she added, “Ha… Then I guess you’ll just have to teach me then, won’t you?”

“Perhaps… ah…” 

The next few minutes were mostly silent, save for the occasional moan from either of them. Sweat rolled down Edelgard's forehead as she gazed down at Byleth, her face as red as a cherry. She'd guided his hands back to her breasts and prompted him to fondle her as one of her own hands moved down to grasp her clit. In time she'd have to formally introduce Byleth to it, but that could wait. RIght now, she couldn't exactly complain about her newfound fullness... 

Waves of pleasure washed over Edelgard's form as she continued to flick and tug at her sensitive little bud. At the same time, Byleth panted as his face grew hot. He could spend an eternity like this, but his body was beginning to fail him as his cock begged for release. "Edelgard... I... think I'm close..." 

"It's okay," she said between pants. "Y... y-you can do it inside me..." 

Byleth was far too enraptured by the girl bouncing on top of him to protest, even while aware of the potential risks. As she began to move faster and faster, he wrapped his arms around her and brought her close. He took in her scent as they continued to fuck, and Edelgard bit down hard on his neck as he grew closer to completion. "Edelgard... I... I love - !" 

"B-B-Byleth!" 

He cried out, arms around her back. Edelgard moaned into the crook of his neck as she felt his warmth fill her up. She'd known all too well what this could mean, but nowhere in the books did it say that it would feel this  _good_. She could only pant as she ran her tongue along his jawline before meeting him in a kiss. Byleth ran a hand through her long white hair as she rested both hands in his own hair. 

"Th... that was incredible," Edelgard said, gasping for air. She gazed at him and gave a small grin. "I... had no idea that would be so..."

"By the Goddess," Byleth groaned, pinching the bridge of his nose. "Edelgard, I... I'm sorry. I promise to take full responsibility for - " 

She pressed a finger to his lips and giggled softly. "It's fine. In truth, I had a feeling things might escalate, so I had some contraceptive herbs this morning..."

"You're kidding...! Where did you even...?"

"An outside source." She nestled into the crook of his neck once more, kissing the area where she bit him. She trailed a finger along his chest and said, "I promise not to tell if you don't..." 

Byleth didn't have to be a genius to come to a conclusion. "... Alright. Your secret's safe with me." 

"And yours is safe with me," Edelgard said, smiling. "Teach... Byleth... I love you." 

She pulled her head up to kiss him again, and the kiss she received was just as gentle. Byleth pulled back with reddened cheeks, but he smiled back all the same.

"I love you too, Edelgard. Now and always."


End file.
